Triazoles, especially tolyltriazole, are corrosion inhibitors used for antifreeze and are also used in water treatment applications. Tolyltriazole is manufactured by reacting o-toluenediamine with sodium nitrite and hydrochloric acid. The crude material is then distilled under reduced pressue to give a white solid. This material is sold as such or as an aqueous solution. The disadvantage to this process is that the product must be distilled, a procedure which may be hazardous (C&E News, May 14th, 1956, reports that an explosion occurred during benzotriazole distillation).
U.S. Pat. No. 3,637,514 discloses a method of preparation of tolyltriazole in which a fractional distillation procedure is used. Similarly, in Heterocyclic Compounds, Elderfield, (1961), volume 7, chapter 5, pages 384-425, no suggestion is made of a procedure to prepare tolyltriazole without the use of distillation.
Organic Syntheses, collective volume 3, pages 106-108 teaches a method of preparation of 1,2,3-benzotriazole in which the product is distilled.